As the yo-yo swings in front
of you, bring your non-throwhand down on the string as close to the
yo-yo as possible without touching it. (The closer your finger is the
more likely you will land i on the string.)

Dismount from the trapeze how ever you like.
In the video a ferris wheel dismount is done. But the easiest way when
first learning is to just pop the yo-yo back off the string and then
catch.